Adjustable tension chain saw machine



June 29, 1948.

A. w. MALL. x

ADJUSTABLE TENsIoN CHAIN sAw MACHINE s sheets-sheet 1 Filed March 17, 1944 M VEN TOR @www w, Wide,

A. /v. MALL ADJUSTABLE TENSION CHAIN SAW MACHINE June 29, 1948.`

Filed March 17, 1944 3 Sheets-Sheet 2 Tfr/6.5

Kfz

i. Fia. 6

//l/E/VT'OR @man w. 777.210 ay MAJ-Kazza.

A TfOR/VEY June 29,194. y A. w MALL 2,444,138

ADJUSTABLE TENSION CHAIN SAW MACHINE Filed Maon 17, 1944 s sheets-sheet s ATTORNEY Patented June 29, 1948 oFFicE ADJUSTABLE TENSION CHAIN SAWV MACHINE Arthur W. Mall, Flossmoor, Ill., assignor to Mall Tool Company, Chicago, Ill., a corporation of Illinois "Application March 1v, 1944, serial No. 526,861

i r l `My invention .relates to chain saw machines of the type which are used primarily for felling and bucking trees and has as its general objective the provision of an improved sawing machine.

My invention also relates to an improved method of felling 'and bucking trees.

One object of my invention is to provide a chain saw machine havingtwo engines to drive the cutting chain'.

Another object of my invention is to provi-de a simple device for adjusting the tension of the cutting chain and for maintaining constant chain tension as adjusted. n

vAnother object of` my invention is to provide novel means for lubricating the chain.

A further object ofv my invention is to provide a compact arrangement of the mechanical parts and castings supporting same so as to reduce the over-all weight of the sawing machine and so as to better withstand the constant pounding action to which these sawing machines are subjected when cutting a tree.

A still further object of my invention is to provide a new method of felling and bucking trees which method is accomplished largely through improved mechanical `features of `my sawing machine.

Other objects and advantages will` become apparent upon reading the following specification and uponexamination of the drawings in which:

AFig. 1 is an end view of one of the engines shown partly in section Fig. 2 is a fragmentary top view in section of the engine shown in Fig. 1;

Fig. 3 isa perspective view of my sawing machine as it is used When bucking a fallen tree;

Fig. 4 is a perspective view of my sawing ma; chine as it is used to fell a, standing tree;

Fig. `5 is a'detail top View in section of the sleeve device into which the chain tension adjustment screw is threaded; and

Fig. 6 is a detail side view in section of the device shown in Fig. 5.

In general my chain saw machine comprises two internal combustion engines A and B mounted at either end of a chain guiding plate C about which the cutting chain D is trained.

lReferring to Fig. 1 I have shown one of the engines which is preferably a two cylinder, two stroke engine. The engine shaft 2 extends outwardly from the engine housing 3 and the outer end of said engine shaft is journaled in a sleeve bearing 4 which is pressed into cover housing 5. An intermediate housing 6 is interposed between engine housing 3 and cover housing 5.

2 Claims. (Cl. 143-32) sleeve 9 so as to berotatable at all times with the engine shaft. p y

A pinion `ll'l is provided with a shank portion Il on which the driven clutch member 8 is mounted. Driven clutch member 8 is rigidly secured to pinion l0 by nut vI2 so as to be rotatable` therewith. A sleeve bearing I3 is pressed into pinion I0 so as to be rigid therewith. `Driven clutch member 8 is thus rotatably mounted on` engine shaft 2. When the engine shaft 2 reaches a predetermined speed 0f rotation, the centrifugally actuated driving clutch member engages the clutch lining I 5 ofv driven clutch member 8 and imparts rotation thereto.` A speed reducing spur gear I6 meshes with pinion I0 to impartrotation to sprocket shaft Il. The sprocket shaft Il is supported at each end by anti-friction bearings i8 and I9 respectively. A bearingretainer cup 20 is formed in the wall of engine housing 3 and a second bearing retainer 2l is formed inthe wall of housing 6. At the free end of sprocket shaft I1 a driving sprocket 22 is mounted preferably by being splined thereto. The sprocket 22 drives the cutting chain D. It is significant'-` to note that the exterior wall of housing 6 is pro-v4 vided with an outwardly extending wall portion 25 which in conjunction with the underneath wall 26 of cover` 5 forms la protective covering for the cutting chain for safety purposes. It is: to be also noted that the plane dened by the: outermost tip of wall 25, said tip being designatedlv 22', and the outer surface 28 vof cover 5 is closely adjacent the plane in which the sprocket 22 lies, thus when a tree is being felled,` the cutting chain can be lowered to within an inch or so ofthe ground thereby leaving little or no tree stump after the tree has been felled. Fig. 4 illustrates how close the cutting chain is to the ground when felling a tree. Secured to the upper end of housing 6 is another housing 29 which forms the upper part of the fuel tank. The fue1 tank is lled with gasoline and, as is customary in two cycle engines, the lubricating oil for the pistons and cylindersis mixed in with the gasoline.` The exhaust gases from the cylinders travel into the exhaust chamber 30. The exhaust gases are partly made upof the lubricating oil in an atomized state and one feature of my invention is to utilize these exhaust gases for lubricating the cutting chain, thereby;

eliminating the necessity of a separate lubricat ing system for the cutting chain. I have provided a tubular pipe 3| which extends outwardly from the exhaust chamber and terminates adjacent the cutting chain. The exhaust gases are thus expelled from the exhaust chamber 30 through pipe 3.1 from which they are projected directly onto` the Cutting chain.

The lubricant carried by the exhaust gases thus lubricates the cutting chain and at the same time the exhaust gases also serve to blow saw dust away from the cutting chain.

Rigidity between the exhaust chamber 30 and housing 3 is obtained by means of an angle iron 33 being secured therebetween by means ot bolts and nuts 34 and 35 fastened to bosses 36 and 31.

One significant feature of my invention is the.

compactness of my engine and its associated driving parts. By locating the driving pinion 'l0 rearwardly of the automaticv clutch assembly, I have made .it possible to locate the driving sprocket inwardly relative to the engine thus reducing the overall length of the engine and associated par-ts. Thisprovides a more rugged construction which isbetter able to withstand the pounding action to which these chain saw machines are now subjected.

Referring .to Fig. 2 I have shown a novel means for adjusting the tension of the cutting chainand for maintaining the tension as adjusted. The cutting, chain is trained about the sprocket 22 and the chain guiding plate C, said chain having tongueport-ionsl (not shown) which ride in the slot 4l) (shown in dotted lines) in guide plate C.

` The guide plate C is longitudinally movable relative. toV its supporting housing 6, the extent ofsuch movement being determined by the length of .slot 4l in guide plate C. The slot 4| is just wide enough to. accommodate the Shanks of locking bolts 42 and 43 and the boss 44 which is integra-l with housing 6 and extends into slot 4| toy guide the movement of guide plate C relative .to housing 6, assuring rectilinear movement thereof.

It is significant to note that the apparent.

walls in housing 6 as indicated by lines at 4'6 and'lin Fig. 2 are for the purpose ofindieating.v a different sectional plane of the chain tension adjustment screw 48 and its supportingbosses 49 and 5D which are integral with hous-` ing: and which are located in a plane slightly above the plane dened by the cross sectioning. in .the remainder of the drawing of Fig. 2. The

adjusting screw 4-8 is rotatably mounted in bossesV 44.1` andv 5l), and extends through sleeve member l'by screw. thread engagement. The sleeve member 5:1" has al threaded bore 52 which receives the adiusting'screw 48 and also has a threaded bore- 5.3 which receives locking bolt 43 as shown in.,

Fig. 6.

It'. issi-gnicant to note .that housing 6 is provided With a rib 54 which rides against guideV plate C. On the side of the guide plate C opposite the rib a pair of washers 55 and 55 provideV screw 48 and screw 48 is turned causing sleeve.

member 52 and bolt 43' to move outwardly away from sprocket 22. When bolt 43 reaches the end of? sloty 4t in guide plate C, it engages wall 582 al?l the end of slot-42| and causes the guide plate.

C to move outwardly away from sprocket 22 thereby tightening the cutting chain. As soon as the desired chain tension is obtained by turning screw 48, then bolts 42 and 43 are tightened against the guide plate C, securely clamping said guide plate in the desired position of adjustment relative to sprocket 22.

Referring to Fig. 3 I have shown my twinengine chain saw machine as it is used in bucking a fallen tree and in Fig, 4 as it is used in felling a standing tree. Heretofore it has been necessary inV using a gasoline engine driven chain saw machine, to rotate the cutting chain and its guide plate relative to the engine in order to fell a tree, the reason being that the gasoline engine has to be maintained in an upright position in order to operate. In my engines I use a diaphragm type of carburetor which permits the gasoline engine to be tilted in any position, forward or backward or on either side, and as a result of this, my new methodof felling` and bucking trees is achieved- My method of felling and bucking a tree with a gasoline engine driven chain saw consists of al series of continuous steps forming a continuous operation, uninterrupted by adjustments to the sawing. machine. It is signicant, first, .to note the handle arrangement which I have provided` for my machine as my method of fellingl andA bucking. trees is partly dependentuponthis-particular type of handle arrangement.

One handle member Si) is secured to the central region of the engine and extends angularly downwardly and then outwardly away from the engine, terminating with a hand gripping portion 6|. Viewing Fig. 4 it is to be noted that the hand gripping portion y6l. lies in a plane which. is approximately common with the plane defined by the chain guide plate C'and the cuttingA chain D. A second' handle member 62 is secured to a boss 63 on the engine. preferably formed of' two sections'whichmay be welded together at 64. One portion 56- of handle member 6,2 extends` angularly upwardly and,

then outwardly away from the engine, terminating in ahand gripping4 portion 6'5.r 'Ihe handle portion 6B forms a mate for handle member ll and the plane dened by these two'handle members is at right angles to the plane deined` by the guide plate C andv cutting chain D. Thus when bucking a fallen tree, as viewed iny Fig. 8, the operator grasps hand .gripping portions El andf65. The spacing of these handle members 60 and 66 permits balancing the sawy to assu-re that the-cutting chain progresses through thelog in a, vertical direction and in aV straight line:

cut.

Handle member 42 is provided with a second kfelling a tree, hand' gripping portions 64% and 6a are grasped by the operator. it will be noted that hand gripping portion Gif is located on the opposite sideofithe-enginefrom handle 63 and viewing'Fig. 4 it`willibe`notedfthat it is located' at the under side ofthe engine whereas handle BSI is located at the upper si'cleof? the engine. Thus the machine iswell balanced inthe' other hand beingv usedf t'o grasphaiidleli and" Handle member 52 isr Viewing Fig. 3'

handle 65 rests against the back side of the arm, thereby giving the operator a tri-cornered balancing condition, which is desirable when felling a tree.

The continuous method of felling and bucking a tree comprises the steps of grasping handles 6| and 69 with handle 65 resting against the back side of the arm which carries handle 6|. An operator is at each end of the saw, the cutting chain being urged against the tree while the cutting chain progresses through the tree. As soon as the saw has progressed suiiiciently far through the tree trunk, so that the guard bar 'l2 is Within the tree trunk, it may or may not be necessary to drive wedges into the kerf to prevent pinching While the saw continues cutting through the tree. When the tree begins to fall, the operators may retract the sawing machine from the tree while still grasping handles 6| and 69. Then, While still grasping handles 6|, the sawing machine is turned a quarter of a turn until the cutting ,chain and guide plate are in a vertical position as viewed in Fig. 3.

The operators grip on handle 69 is released and handle 65 is then grasped. Then the operators carry the sawing machine along, one on either side of the fallen tree, until the desired location for therst bucking cut is reached. The cutting chain is then permitted to come into contact with the tree and cuts through the log, the weight of the engines being suiiicient to urge the cutting chain through the tree. Thus it can be seen that my method of felling and then buck,- ing a tree consists of a series of continuous steps which are uninterrupted due to the fact that it is not necessary to stop and make adjustments to the sawing machine during the steps of felling and bucking a tree.

Having thus described my invention, what I claim is:

1. A chain saw machine comprising a power unit, a chain guiding member extending therefrom, a support member associated with the ypower unit, a sprocket shaft carried by the support member, a sprocket on the sprocket shaft, a cutting chain trained about the sprocket and chain guiding member, a slot in said chain guiding member, a pair of bolts extending through the slot, one of said bolts being threaded into the support member, an adjustment screw carried by the support member and being at right angles to the other two bolts, a sleeve member threaded onto the adjustment screw, the second of said bolts having screw-threaded engagement with thesleeve member whereby upon turning the adjustment screw, the second bolt moves relative thereto.

2. A chain saw machine as described in claim 1 wherein a boss on the support member extends into the slot in the chain guiding member.

ARTHUR W. MALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date '1,342,213 Hanson et al June 1, 1920 1,467,150 Frere Sept. 4, 1923 1,617,565 Bens Feb. 15, 1927 1,710,970 de Northall Apr. 30, 1929 1,802,129 Vaccari Apr. 21, 1931 1,952,270 March et a1 Mar. 27, 1934 2,051,195 Arsneau Aug. 18, 1936 2,109,702 Lange Mar. 1, 1938 2,165,524 Wolf July 11, 1939 2,348,612 Deacon May 9, 1944 2,357,953 James Sept. 12, 1944 FOREIGN PATENTS Number Country Date 274,348 Great Britain July 21, 1927 402,765 Great Britain Nov. 28, 1933 539,956 Great Britain Sept. 30, 1941 651,391 France Oct. 9, 1928 676,377 Germany June 3, 1939 OTHER REFERENCES Page 106, Popular Science magazine for July 1941. 

